DESCRIPTION (Adapted from the application) The Molecular Biology Core?s purpose is to provide services in the utilization of molecular biological techniques and facilitate implementation of advances in molecular biology to IBD research. The serves and reagents provided are intended to be cost effective which include: synthesis and labeling of oligonucleotides and other nucleic acids; production, storage and distribution of specialized cDNA libraries; preparation, storage and distribution of cDNA probes and plasmid vectors; storage and distribution of biological reagents (eukaryotic and bacterial cell lines, phage stocks, RNAs purified from tissues and cell cultures, genomic DNA for chromosomal localization and rarely used nucleic acid modifying enzymes; production and distribution of polymerase; generation of novel lines of transgenic mice and ; development and distribution of reagents for gene expression profiling (oligos for differential display, development of DNA microarray). The transgenic core is in collaboration with the Molecular Biology Core of the GRASP Center at the New England Medical Center. Injection and implantation occurs at the NEMC and the resulting animals are returned to CSIBD for genetic analysis and use. In addition to the above services, the Molecular Biology Core also has an educational mission. The Core will teach a variety of techniques as well as for the past two years the Core has organized an annual intensive, hands-on course in commonly used molecular biological techniques designed for new students and postdoctoral fellows (two weeks, full time). This is done in conjunction with a summer lecture course "Current Techniques in Molecular Biology". In this current grant application there are new services proposed. The Core will set up training and enhanced access to bioinformatics technology, enhanced support for the production of mice with targeted gene deletions and replacements and support for gene expression profiling by differential display analysis and development of DNA microarrays. An IBD chip is proposed which would contain 8000 genes on a glass slide to study human, mouse and rat tissue with a proposed cost to investigators of $175.